DLARF(1) LAPACK auxiliary routine (version 3.2) DLARF(1)NAME
DLARF - applies a real elementary reflector H to a real m by n matrix
C, from either the left or the right
SYNOPSIS
SUBROUTINE DLARF( SIDE, M, N, V, INCV, TAU, C, LDC, WORK )
IMPLICIT NONE
CHARACTER SIDE
INTEGER INCV, LDC, M, N
DOUBLE PRECISION TAU
DOUBLE PRECISION C( LDC, * ), V( * ), WORK( * )
PURPOSE
DLARF applies a real elementary reflector H to a real m by n matrix C,
from either the left or the right. H is represented in the form
H = I - tau * v * v'
where tau is a real scalar and v is a real vector.
If tau = 0, then H is taken to be the unit matrix.
ARGUMENTS
SIDE (input) CHARACTER*1
= 'L': form H * C
= 'R': form C * H
M (input) INTEGER
The number of rows of the matrix C.
N (input) INTEGER
The number of columns of the matrix C.
V (input) DOUBLE PRECISION array, dimension
(1 + (M-1)*abs(INCV)) if SIDE = 'L' or (1 + (N-1)*abs(INCV)) if
SIDE = 'R' The vector v in the representation of H. V is not
used if TAU = 0.
INCV (input) INTEGER
The increment between elements of v. INCV <> 0.
TAU (input) DOUBLE PRECISION
The value tau in the representation of H.
C (input/output) DOUBLE PRECISION array, dimension (LDC,N)
On entry, the m by n matrix C. On exit, C is overwritten by
the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'.
LDC (input) INTEGER
The leading dimension of the array C. LDC >= max(1,M).
WORK (workspace) DOUBLE PRECISION array, dimension
(N) if SIDE = 'L' or (M) if SIDE = 'R'
LAPACK auxiliary routine (versioNovember 2008 DLARF(1)
